Hydraulic power unit



Dec. 11, 1945. MELUNGER 2,390,957

HYDRAULIC POWER-UNIT Filed Oct. 28', 1942 5 Sheets-Sheetl fi mwar zzzr er Dec. 11, 1945. I MELUNGER r 2,390,957

HYDRAULIC POWER UNIT Fild Oct. 28, 1942 5 Sheets-Sheet 2 Dec. 11, 1945. A. G. MELLINGER HYDRAULIC POWER UNIT Filed Oct. 28, 1942 5 Sheets-Sheet s A. G. MELLINGER 2,390,957

HYDRAULIC POWER UNIT Dec. 11, 1945.

' Filed Oct. 28, 1942 1945- A. G.- MELLINGER 2,390,957

HYDRAULIC- POWER UNIT Filed 0ct 28, 1942 5 Shets-Sheet 5 7E8? Kl Patented Dec. 11, 1945 UNITED STATES ,PATENT OFFICE HYDRAULIC POWER UNIT Arthur G. Mellinger, Lancaster, Pa. Application October 28, 1942, Serial No. 463,668

10 Claims.

This invention relates to a hydraulic power unit and has for an object to provide such a unit including a stator and a rotor constructed and assembled in a manner whereby fluid pressure is transformed effectively into rotary motion.

The invention also has for an object to provide a unit of this kind including a stator and a rotor and wherein said parts are provided with coacting abutments and wherein the abutments carried by the rotor are mounted for movement into effective or ineffective positions and wherein the fluid under pressure is employed to maintain such abutments in requisite positions during their periods of effectiveness.

The invention consists in the details of construction and in the combination and arrangement of the several parts of my hydraulic power unit whereby certain important advantages are attained, as will be hereinafter more fully set forth.

In order that my invention may be better understood, I will now proceed to describe the same with reference to the accompanying drawings, wherein:

Figure 1 is a sectional view with parts in elevation and of a diagrammatic character illustrating a power unit constructed in accordance with an embodiment of my invention.

Figure 2 is a fragmentary view in top plan of the valve structure as herein embodied.

Figure 3 is a sectional view taken substantially on the line 3-3 of Figure 1, looking in the direction of the arrows.

Figure 4 is an enlarged sectional view taken substantially on the line 4-4 of Figure 3.

Figure 5 is an enlarged detailed sectional view taken substantially on the line 55 of Figure 3.

Figure 6 is a sectional view taken substantially on the line 65 of Figure 1, looking in the direction of the arrows.

Figure 7 is an enlarged detailed sectional View taken substantially on the line 1-7 of Figure 6.

Figure 8 is a sectional view also taken substantially on the line 3-3 of Figure 1, with the rotor in fragment and diagrammatically indicated, a second position of the rotor fragment being indicated by broken lines.

Figure 9 is an enlarged detailed sectional View taken substantially on the line 9-9 of Figure 8.

Figure 10 is an enlarged detailed sectional view taken substantially on the line Iii-4B of Figure 8.

Figure 11 is a view'in perspective of one of the blocks 63 unapplied.

Figure, 12 is a view in outer end elevation of said block.

Figure 13 is a view in perspectiveof a gate valve unapplied.

Figure 14 is a view in perspective of a back plate or block unapplied, and

Figures 15 and 16 are fragmentary sectional views illustrating a modified structure.

As disclosed in the accompanying drawings, S denotes a stator including a head I of desired configuration and dimensions and which has a sleeve 2 at its axial center with the bore 3 of the sleeve disposed through the head I. The outer or free end portion of .the sleeve 2 is adapted to be rigidly and nonrotatably anchored, as at 4, to a suitable support depending upon the character of the general assembly of which the power unit is a part. In Figure 1 of the drawings, the supporting member M is disclosed as a suitably held tubular member having an end portion snugly received within the outer portion of the'bore 3 of the sleeve 2.

The wall of the sleeve 2 at the inner portion thereof is provided with the ports 5 and 6 spaced apart in a'direction lengthwise of the sleeve 2 but herein disclosed as in relatively close relation. One of these ports 5 or 6 serves as an outlet port when the other is being used as an inlet port, as will hereinafter be more particularly referred to. These ports 5 and 6 have in communication therewith and leading therefrom the pipe lines or conduits l and 8 respectively which also have required communication with a valve structure V of the type embodied in Patent No. 2,178,182, which issued October 31, 1939, and which valve structure allows for thereversing of the flow, of the fluid to the ports5 and 6.

It is to be stated at this time, however, that in this valve structure the rotary valve members 9 are operatively connected, as at [0, for unitary rotation, and in such a manner that when one of the valve members 9 is opened with respect to the inlet of the valve structure, the other is closed and, of course, whenone of said valve members is in a position to close its associated exhaust, the other. valve member is in open position with respect to its exhaust. It is by means of this valve structure that the rotor R of the unit may be caused to rotate as desired in either direction.

Threaded or otherwise tightly held within the bore. 3 of the sleeve 2 outwardly of the ports 5 and 6 is a head or plate II which closes the bore of the sleeve 2 and the inner end of the bore 3 of the sleeve 2 is directly in communication with the cylinder or bore ll of material diameter and depth provided in the outer face of the head I of the stator. The inner portion of the inner or base wall I4 of the cylinder or bore l2 at its communication with the bore 3 of the sleeve 2 is rabbeted, as at I5, to snugly accommodate a portion of a conventional ball bearing assembly I6 which is also snugly fitted upon an outstanding hub sleeve II comprised in the rotor R. This ball bearing assembly I6, as herein disclosed, is effectively maintainedin appliedor working position by anannular-inember I8: which is tightly but rotatably received within the inner or adjacent portion of the bore 3 of the sleeve 2.

The wall at said inner portion of the bore 3 of the sleeve 2 is provided therearound with. a. continuous groove or channel I3 concentric to the axial center of the bore 3 of the sleeve 2 and p The peripheries of the plates 3I, 32 and 33 are provided therearound with the grooves 36 which register with. the properly positioned grooves 31 I provided in the, inner wall of the applied memwhich groove or channel I9 registerswithra.sur-- V rounding groove or channel 20 provided in the periphery of the annular member I8. disclosed, these grooves or channels I3 and; 20 are substantially V-shaped in cross section with their apices inwardly disposed and which resi tering grooves or channels in the'assembly. of the. parts snugly receive.packingsegments 2'I'. J

The side wall 22 of the. cylinder or bore. I2 of the head I is provided with thecircumferen tially disposed andv relatively deep grooves. 23-, herein disclosed as twofin number and: suitably spaced in a directionaxial of thehea'd I.. These grooves 23 extend substantially entirely around. the head I 'but are in reverserelation, as is clearly illustrated in Figures 3, 6, and. 8 of' the drawings. One of these grooves, 23- is inus ewhen the rotor R is rotating inone direction and. the second groove 23. isin use when the rotor is rotating in the opposite direction. There. is, however, no operative connection. between, thev two grooves 23 as the functioning; of. oneisen,- tirely independent of the functioning of the other.

One end portion of each of the grooyes,2 3 come municates with an outwardly disposed port. 24

provided in the head I and in. communication;

of the sleeve 2, and herein. disclosed as diamet--- rically opposedto the. ports 5 and 6, respectively.. Each of these. pipe lines or conduits 25. has in.-

terposed therein a. conventional check. valve, 28

which operates, to prevent retrograde flow: through the pipe line or conduit 25. with respect. to the head I.

As herein embodied, the inner faces. oi. the, grooves 23 are open but said open faces are closed by an annular member 29 snugly fitting within the peripheral portion of the cylinder or. bore I:2, as is clearly illustrated in the accompany drawings. This member 29 is fixed or. non-rotatable. with respect to the head I. Any means may, be. employed to assure the effective. locking. of the; applied member 29 and head I but, asparticur larly illustrated in Figure I of the drawingssuch anchorage is secured. through. the 'medium of the suitably positioned conventional dowels;

The rotor R includes two plates 3I. and.3.2,

each of material thickness. and of. a. radiusto.

snugly engage within the member 29. but. free.

bled relation by the headed. members. 3di=fiteelyi 75,

AS herein her 29, said grooves 36 and 31 being V-shaped in 01311? with. their apices inwardly disposed and saidgrooves 36 and 31 snugly receive the segmental packing elements 38.

After the rotor R has. been. properly applied within the. stator. S, the. outer end: of the. bore or cylinder I2. of the. head. I is closed, in. the. present. embodiment. of the invention, by a cap or head. plate. 39; removablyheld to the head I by the. bolts. 41)}. although, of. course, other means for securement of this. capor head. plate 39 may beused as preferred. Asis clearly illustratedin Figure 1. of the drawings, the outer. face of the plate 34. has close. contact with; theinner face of the applied cap. plate. or head. 39-. while the outer face of the. plate. 32. has close contact. with. the. base wall. I41 of. the. boreor. cylinder I 2. The plate 3I at its axial center is provided with an' outstanding power, take-off spindle.- or. shaft. 4| andfthe cap. or headlplate39 carriesthe conventional ball bearing, assemblies 42.

The face of'the. plate3l. opposed to the intermediatev plate. 3.3,. or more. particularly the adja- 40. cent gasket plate 35, has its central portioncut out to providev a, chamber 43 which. has its outer face closedflby, the. intermediate plate 33-, or. more particularly one. ofthe gasket plates 35. The. intermediate plate 33' at its axial center is; provided withv an opening 44 into. whichthreads an end portion of a tubular. stem. 45 open. at both ends. As is clearly illfustrat'ediin. Figure 1, this stem 45 extends. axially through thehub sleeve I.'I herein-before referred. to. and. is of a. length to extend a required distance beyond. the outer end of this leeve, I].

Rigidly mounted, as at. 46,. upon the. outeror free endportion of this stem 45 isacirculan plate 41 which snugly flts'within. the. bore 3 of the sleeve 2 and, as illustrated in, Figurev 1, it. is. to. be noted that the. stem 4 5I.isof such length to allow this plate 4.1 to. be positioned between the ports; 5 and 6 and 26 andQZI. It is also tov be notedthat the stem. 45 is. of a. major diameter materiallylessthan the diameter. of. the. boreof the sleeve I! for a purpose to be hereinafter pointed out. The periphery of. the plate 41 is providedtherearoundwithier groove 48 whichregisters with agroove 49 in the adjacent inner face-01 the sleeve 2 These grooves 48 and. 49 are V-'-Shaped in cross section with their apices inwardly. disposed. and" snugly receive the segmental packing members 50.

It: is; to: be; stated at: this; time that the stator S including. 'thesleeve2 and. the member 23 is radially halved; as: particularly illustrated. in Figures. 3,, 6.. and 8.-of the drawingato. facilitate the assembly of the motor. The sections of'the head I and. the sleevel areprovided with; the outwardly disposed butting flanges Slwitlrzwhicli coact in a well known manner the holding members 52. It is believed to be apparent, however, that to all intents and purposes, insofar as the present invention is concerned, the head I and the sleeve 2, together with the member 29, can be considered as single units.

Disposed through the peripheral portion of the plate 3i and in communication with the chamber 43 are the outlet ports 53 herein disclosed as two in number and having their outer or discharge ends a substantially diametrically oppos'ed. The inner portion of each of these ports 53 is enlarged, as at 54, to provide a housing which receives the inner end portion of a sliding abutment or vane 55 which moves outwardly and inwardly with respect to the periphery of the plate 33 through a suitably provided slot 56 extending through the peripheral portion of the plate 3i and open at both ends. This abutment or vane 55 snugiy fits within the slot 56 and the outer end portion of this vane 55 is of such dimensions as to snugly and tightly engage, when extended, within one of the elongated channels or expansion chambers 51 provided in the inner face of the member 39.

. In the present embodiment of the invention, these channels, or chambers are three in number and are of equal length. These channels or chambers 57 are also equldistantly spaced around the bore or cylinder l2 and one end 56 of each of the channels or chambers 5f! constitutes a fixed abutment while the opposite end portion of each of the channels or chambers 51 has its base wall disposed substantially tangential to the inner open face of the channel or chamber 51 to provide a cam face 56 to effect the return movement of an extended abutment or vane 55 as the same travels along the cam 59 during the rotation of the rotor. It is preferred that the base wall or face of each of these channels or chambers 5'! has disposed thereover the removable fiber strip 50, said strip extending from the fixed abutment 58 to substantially the outer end of the cam 59.

One of the grooves 23 hereinbefore referred to is coplanar with the applied plate 31 and, as is believed to be obvious in the assembled structure, such groove 23 constitutes an exhaust manifold. The cam end of each of the channels or chambers 57 is provided with an exhaust port 6| extending through the adjacent peripheral portion of the member 29 and having communication with the groove or exhaust manifold 23'. Each of these ports iii in the present embodiment of the invention is substantially midway of a cam 59 although, of course, this position may be varied within reasonable limits as the requirements of practice may deem best.

The wall of the chamber 43 adjacent to the enlarged portion 56 of each of the ports 53 is provided with a pocket 62 in which istightly fitted a block 63. This block 63 is herein disclosed as held in place in a well known manner through the instrumentality of the locking key 63' coacting with the block 63 and an adjacent wall of the chamber 43. It will be obvious, however,'that the block 53 may be otherwise held in place if preferred and for example by the elongated and radially opposed parallel rods 65 secured at their inner ends, as at 66, to the outer end of the block 63 and of a length to have close contact with a portion 61 of the wall of the chamber 43 opposed to said outer end of the applied block 63.

The block 63 has disposed therethrough a bore 68, the outer end of which is in communication with the chamber 43 and the inner or inserted end being in communication with a. port 69 formed in the plate3l and which port is in communication with the enlarged portion 54 of a port 53. The block 63 at its inner or inserted end i provided at opposite sides of the bore 68 thereof with radially disposed slots 70 open at their outer ends and which provide for free passage of fluid under pressure through the cylinder 68 after the piston 'H working within the bore or cylinder 68 has been moved under fluid pressure beyond the inner ends of the slots 10.

With the piston H in this extended position, it is believed to be apparent that the fluid under pressure will flow through the bore or cylinder 69 beyond the cylinder 68 and out through the slots 10 into the port 69 and from the port 69 into the enlarged portion 54 of the port 53 and out through such port 53 into a groove or ex-' pansion chamber 23. During this period of flow, the adjacent abutment or vane 55 is sufficiently extended to offer no hindrance to the flow.

The piston ll, when free of fluid pressure from within the chamber 43, is normally maintained in its retracted position, as illustrated in Figure 6, by the expansible springs 12 encircling the rods 65 and butting the inner face of the block 63 and a cross member 13 carried by theouter or free end portion of the stem 74 carried by the piston H.

One end portion of the cross member 131s herein disclosed as having an offset extension or laterally disposed lug 15 through. which is slidably disposed an end portion of a rod 16. This rod 16 outwardly of the extension or lug l5 has threaded or otherwise adjustably mounted thereon a stop 71 for contact with said extension or lug 15 whereby the movement of the rod 76 in one direction is limited by contact of said stop 11 with the extension or lug l5.

This rod 76 i of a length to have its end portion remote from the extension or lug l5 slidably disposed, as at 78, through a portion of the plate 3| and into the enlarged portion 54 of a port 53. The rod 16 at a desired point intermediate its end carries a surrounding collar 19 and interposed between this collar 19 and the extension or lug 15 is a coiled spring 86. This spring 80 encircles the rod 16 and is ofea tension less than the tension of the springs '12, so that the rod 16 may move inwardly or rearwardly with respect to its port 53 without eifecting corresponding movement of the cross member 13. This spring 80, however, is of sufficient tension to assure outward movement of the rod 16 in unison with the movement of the piston 1| under the pressure of the fluid within the chamber 43.

The extremity of the rod 16 within the enlarged portion 54 of the port 53 is operatively connected by a link 8| with the inner end portion of the adjacent sliding abutment or vane 55, so that as the rod 16 is moved outwardly, this abutment or vane 55 will also be moved outwardly so as to have proper engagement within the successive chambers 51. However, as such projected abutment or vane passes over a. cam face 59, the spring 14 will allow such abutment-or vane 55 to be forced back within the plate 3| but just as soon as the abutment or vane 55 passes over a cam face 59, it will be substantially instantaneously returned within the next or slide. valve 83. Thisvalve '83 has al movemerit: in. a. general direction axially of the plate 3t and when in one position intersects. the: port.

69: to; lose the same againstfiow therethrough. This valve 83 at one endis provided with a; laterally directed tappet 8.4.. This .tappet. is of alength; to snugly and freely extend through. a suitably positioned opening 85 provided in the outer or closed side of. the plate; 3| and is. in;- tendled. tot he. received. within one of a series. of arcuate. grooves 86: provided inv the inner face. of the can or; head plate: 39i These grooves 86. are three in. number and'ane equidistantly spaced aroundthe; plate 39. and..concentric to thetaxistheneofi.

Eachofi thesegrooves 86 isof'alength to allow the valve: 853; to be maintained in an. open positiom during. the travel of an. extended. abutment or; vane 55. irom'sulnstant'ially. the'fixed abut ment. 58' ofzae chamber 5": to the low part of. the cam 59 at the opposite end of said chamber. of. these. arcuate: grooves 83 has its base formed to provide. the oppositely disposed cam faces. 85;, the low" points of which are inwardly disposed with: respectlto: thebottom on base ofthe roove: 86

The. high points: and the: low point y of each of these cam faces 811. are spaced apart: in 'a direction lengthwise of the groove 86 a distance" substantially; equal tothe diameter of the: dischargeend Gi-Ofi each ofitheports53 and each of these: grooves 86 is of such length between the opposed; inner low. pointszy of the cam faces 81 at the: opposite ends; thereof. and. so positioned to allow ,for' the: desired. opening movement of the valve: 831 to commence at the time the forwardportion. of1the discharge end of the port 53 passes beyond aifixed' abutment 58 and the pitch of the cam face is: such that this valve 83 will be entirely opened with. respect to its port 69: when: the discharge enda. of the port 53 has entirely passed beyond the fixed abutment 58;.

portion of the: groove 88 between the cam faces 81: will; allow the valve: 83 to. remain open untilthe-extendedextremityof the sliding abut-- mentor-vane SE closely approaches the low point of the: cam. face 59;. whereupon the. second. cam face 81: the groove. 86- willforce the valve 83 into closed position with respect to the port. 88:. The distancesbetween: the extremities of each. pair of adjacent grooves 86 is such asto: maintain the valve 83 in closed position until: the. tappet. 84 of: the valve 83: is: allowed to enter the receiving; end: portion of the succeeding groove 85;. The valve 83 asis oleamly illustratedin Figure 4 of the drawings, has reciprocating movement within its pocket 82' in a direction lengthwise of the tappet 84 and this valve 83 is: thrown; into. and. maintained in: open position, in. the. present; embodiment of my invention, by the; action. of; a; spring; 88 ot requi'sitetension. As illustratedin Figure: 4 of the drawings, this spring 88: encircles; a. 89- extending outwardly from an endportion. of the gate rah/e283 andi extends within a suitably positioned: opening 93 disposed.throughtheintermediate plate;3 3.. This spring. bears: against the gatevalve 63; and. against the gasket: plate 35 at the side 01 the plate 33.- remote' from the. gate valve: 8-3. llhe: gate. valve 83 is: provided with anoutstanding pin Itishelieved to be; obvious that. while the. rotor is: iii'rotation, the fluid within the channel or: chamber 51' in. advance of the extended abutment on vane:- 55 will; be. forced. out through. an:

' exhaustport (it into the associated exhaust manifold 23.

the sleeve: I1, hereinbefore referred to, defines a central. opening: 82: through the. second or inner plate" 32i oi the; rotor- R and. which opening 9-21 provides communication with the central chamber: 43 which; as: illustrated in Figure l, is closed by the: intermediate plate 33 or more particularlythe'. adjacent. overlying gasket plate 35.

As: the. general. constructions of the plates 3| and: 32, together with the mechanisms arranged therein, are. identical, it isbelieved that for clarity" and brevity in. disclosure, the corresponding features of these two plates. 3:! and. 32. can. be properly identified: by the. same reference char.- acters; .It is also pointed out that for all general practicalpurposes theclosed side of the head I and the removable cap or. head plate. 39': are.

89 which is encircled by the spring 88 to"; increase It is to) be stated, however, that in practice when the fluid pressure is directed within. the centralv chamber 43 of one. of. the plates 3| or 32:, such flow iscut. oil fromthe central: chamber 43 of. the second plate. In. other words; each of. the plates 3| or 32 may be considered. as. constituting acentral operating unit effective-when the other is ineffective. and without any coaction: therebetweenl. It will. be obvious that the tructure associated with. one of the plates: 3!- or: 32; is. to effect: rotation of the rotor R in one direction; while: the. structure and arrangement associated. with the. second. plate. 3| or 32 isv to efiect; rotation. the opposite. direction. and, of

coursa. the necessary parts of the. mechanismscarried. by or: associated with said plates 3|- and 32 are in. proper reverse arrangement. It is to be pointed: out,. however,. that while the flow of the fluid under pressure. into the chamber 23: ofthe plate 31'. is through the. tubular stem. 45, the fiow of such fluid into the central chamber 43 of the: inner plate. 32 is through. the hub. sleeve H: which; has itsv boreof@ sufllcient. diameter in. excess. of: the: major diameter of the. tubular stemldi' to" readily allow such fioW In. the embodiment of the invention: as particularly illustrated in.Fig.ure 1;, it is to benoted' that when the. pressure. isto the central chamber 43 of the: inner. plate 32 through the sleeve the discharge of. the fluid from. theexpansion chambers. 51 willbe through the sleeve 2 at the remote. side oi the plate. 41 and vice versa.. It isalso believed. to be apparent from the. foregoing that. when. the fluid. pressure is being delivered to: the. central chamber 43 of one. of. the plates it!v or 32,. the sliding abutmentsor vanes 55' of the second. plate 3!. or" 32 will. be maintained in; their fullyretracted position, as illustrated; in Figure. 6,. as,. of course, said abut ments or vanes; 55 will only be extended. when pressure is imposed upon. the pistons ll; associated.withsuchabutxncnts or. vanes 55.

The member 29 in; advance of and. closely adjacenteachofthefixed: abutments 5& is provided in: its. inner face with. a radially disposed and relatively=.deep recess. 91. This. recess: 81- is of. desiredlength. and is. positioned in the same-ra diaL plane: as the. outlet ports 53. ot'the associated plate; 3|: or .32. and. extends across the. member 29 beyond opposite sides: of; the path of: travel of said ports 53 when the rotor R is in action; Subs-1! fltting; within. this: recess 91 is apacking 'ulated or controlled as desired and, of course,

plate or block 98 which is maintained in close contact with the adjacent periphery of the plate 3| or 32, as illustrated in Figure 5, by an expansible coiled spring 99 interposed between the packing plate or block 98 and the base or inner end of the recess 91.

In assembling the halved parts of the head and annular member 29, the same are effectively set and initially maintained in desired relative assembly by the conventional use of dowels I00, as indicated in Figures 3 and 8 of the drawings, although, of course, if desired other means may be employed for this purpose if deemed-expedient.

While the invention as herein disclosed is particularly embodied in connection with fluid, such as oil under pressure, it is believed to be apparent that with but slight change it could be used in connection with compressed air or steam as the motive force and when so used the discharge manifolds 23 can deliver direct to the atmosphere or otherwise as may be preferred, as the particular arrangement of the pipe lines or conduits 25 herein disclosed will not be needed.

When a valve 83 is closed, there is a tendency to balance the pressure under the piston 'II but when this valve 83 is opened, the pressure will be allowed to go through the exit port 53 and while the valve 83 is open, the only way whereby the pressure may equalize itself under the piston H is for the load on the drive shaft to be too great for the amount of pressure being used. As one of the valves 83 is always in an open position, due to the timing cams, it is believed evident that there would be a constant flow of pressure in any one of the channels or chambers 51 at all times, thus assuring rotation of the rotor R since this rotat on is caused by the thrust of the pressure between the fixed abutments 48 and the movable vanes 55. It is particularly pointed out that the only function of the piston II and the associated spring 12 is to withdraw a vane 55 back into the rotor when the reverse side is being used. For this reason each of the springs I2 is relatively weak as it does not have to perform any other funct on than to hold its associated vane 55 back in place against the centrifugal force of the trough on the reverse side of the unit.

In Figures 15 and 16 of the drawings is illustrated a mod fied structure as particularly pertains to the gate valves 83 and more particularly to provide means whereby the tens on of the coiled spring 88' associated with each of said valves 83' may be regulated without disassembling the motor structure or with the same advantage any one of such springs may be readily removed and replaced.

In this modification of the invention, the suitably positioned opening IOI in which is received the spring 88' registers with an opening I02 which is disposed either through the plate 3| or 32' which is adapted to be brought into register with a suitably positioned opening I03 disposed through either the removable cap or head plate 39', as illustrated in Figure 15, or through the fixed head I'. It is only required that there be a single opening I03 through either the cap or head plate 39 or the head I' as the rotor R can be readily rotated to bring the required opening I02 into register with the opening I03.

Insertible through an opening. I03 for threading into a registering opening I02 is a plug I04 which provides an abutment for a spring 88'. By shifting this plug I04 lengthwise of the opening I02, the tension of the spring 88' may be regupon complete removal of a plug I04 a spring 88' can be readily removed and replaced. Normally each of the openings I03 is closed by a removable *plug I05.

What I claim is:

1. A power unit comprising a cylinder, a rotor fitting in said cylinder, said rotor'in its central portion having a chamber to receive a fluid under pressure and also having a plurality of ports spaced circumferentially therearound and opening and discharging through the periphery of the rotor, movable abutments carried by the rotor, there being one of said abutments adjacent to each of the ports, the encircling wall of the cylinder having a circumferentially arranged series of channels in the plane of the ports of the rotor, an end wall of each of the channels constituting a fixed abutment, the cylinder having an exhaust outlet in communication with the opposite end portion of each of said channels, each of the movable abutments upon outward movement extending within a channel to form an expansible chamber with the fixed abutment at one end of the channel, reciprocable pressure actuated elements connected with the abutments and operated by the pressure of the fluid within the chamber of the rotor to move the movable abutments outwardly to extend within the channels of the cylinder, the sa d elements being in the path of fluid travel from the chamber to the ports valves carried by the rotor and interposed between said pressure actuated elements and the ports for controlling the flow through the ports, means for maintaining each of the valves in open position while the ad acent movable abutment is extended within a chamber of the cylinder, and means for maintaining the valves closed during the period the outer or discharge ends of the ports are travsl ng between adjacent ends of the channels of the receptacle.-

2. A power un t comnrisng a cylinder, a rotor fitted within said cylinder, said rotor in its central portion having a chamber to receive fluid under pressure and also having a plurality of ports spaced circumferentially therearound and opening and discharging through the periphery of the rotor, movable abutments carried by the rotor, there being one of said abutments adjacent to each of the ports. with the abutment having a part extending within the port, a piston block within the port and having its bore open at both ends, a piston working in the bore of the block, said piston under the influence of the pressure of the .fluid within the chamber of the rotor moving :beyond the inner open end of the bore to allow the fluid under pressure to flow out through the port, the encircling Wall of the cylinder having a circumferentially arranged series of spaced channels in the plane of the ports of the rotor, one end wall of each of the channels constituting a fixed abutment, the cylinder having an exhaust port in communication with the opposite end portion of each of the channels, an operative connection between the piston working in the bore of the block and the adjacent movable abutment for moving said abutment outwardly as the piston of the block is moved outwardly by the fluid pressure, and means for retracting said piston and abutme'nt when the fluid pressure is ineiTective.

3. A power unit as set forth in claim 2 wherein the operative connection between a piston and a movable abutment comprises a stem carried by the piston and extending within the pressure chamber of the rotor, a cross member carried by the stem, an eXpansibl-e medium interposed between the cross member and the block 'Ior retracting the piston, a rod within the pressure chamber and slidably extending within the port, an operative connection between the inserted-end aof therod and the movable abutment, and .an.operative connection between said .rod andthe :cross :member to move the sliding abutment outwardly ,asthe pmon is moved outwardly by the pressure of the fluid within the pressure chamber.

4. A power :unit :as .set forth in claim 2 wherein the operative connection between vapi'ston and a movable abutment comprises a stem carried by the piston and extending within the pressure chamber of the rotor, .a :cross member carried by the :stem, :an :expansible medium interposed between the cross member and the block for re- 'tracting the piston, a rod within the pressure chamber and :slidably extending within the port, 1

an operative connection between the inserted .end of the rod and the .movable abutment, sa'id rod being slidably disposed through the cross :memher, and :an expansible member operative'ly engagedwith the .rod and the :cross member to cause the movable abutment to move outwardly with the outward movement of the piston :but allowing independent inward movement of the movable abutment.

5. A powerunit comprising a cylinder, a rotor fitting :in said cylinder, said rotor "in its central portion having a chamber to receive a fluid under pressure and also having a plurality of :ports' spaced .circumferentially therearound and opening and discharging through the periphery of the :rotor, movable abutments carried by the 1'0- tor, there being one of said abutments adjacent to :each of the ports, the encircling wall :of the cylinder having a circumferentially arranged series 'of channels in the plane of the ports of the rotor, an end wall of each of the channels constituting a fixed abutment, the cylinder having an exhaust outlet in communication with the opposite end portion of each of said channels, [each of the movable abutments upon outward movement extending within a channel to form an expansible chamber with the fixed abutment at one end of the channel, means operated by the pressure of the fluid within the chamber of the rotor to move the movable abutments outwardly to extend within the channels of the cylinder, valves carried by the rotor for controlling the flow through the ports, means for maintaining each of the valves in open position while the adjacent movable abutment is extended within a chamber of the cylinder, means for maintaining the valves closed during the period the outer .or discharge ends of the ports are traveling between adjacent ends of the channels of the 'receptacle, a face of the pressure chamber of the rotor being open with the head of the cylinder closing said open face, a valve for controlling the flow through each of the ports mounted .for back and forth movement, a laterally disposed tappet carried by each of the valves extending outwardly and freely through the adjacent portion 'of the rotor and disposed toward the head of the cylinder closing the chamber of the cylincler, the inner face of said head being provided therearound with a series of circumferentially spaced channels having their opposite end 'por- .tions formed to provide cam faces, and means for moving the valve member to engage the tappet .of the valve within the groove as the valve acumen being .open withrrespectto its port, contact oI-the tappet with the scam faces moving the 'valve into closed position with respect to its port, each of the grooves being of a length to allow the valve to be maintained in open position during the travel of the adjacent extended abutment from substantially the fixed abutment of a channel of the cylinder to the opposite end thereof, the high 'point of each of the cams of the groove being spaced from the low point in a direction lengthwise of the groove a distance substantially equal to the diameter :of the discharge end of each of the ports.

6. A power unit, comprising a cylinder, a circular rotor fitting in said cylinder, said rotor having a chamber to receive a fluid "under pres- :sure and a fluid passageway leading 'from the chamber through the periphery of rotor, the encircling wall of the cylinder having a circumierentially extending channel therein partly encircling the periphery .of the'rotor in the plane of :said fluid passage, 'a radially movable abutment vane supported for movement transversely of the passage to an outward position in which it extends into said channel and inward from the channel in which it is disposed across and :closes off the passage, a pressure responsive member within :said passage adapted for movement in one :direction zunder' the action of fluid pressure from within said chamber, :an operative coupling between said "pressure responsive ele- .ment and said abutment by which outward movement of the abutment into the channel is effected by the pressure responsive element upon movement of the element :under pressure of fluid from the chamber, andan exhaust outlet incommunication with .an :end .of the channel, said passage opening into the channel between the abutment and the other end of the channel, said operati-ve coupling between the pressure responsive member and the abutment :being of a yieldable character whereby the abutment may be forced inwardly into position transversely of the fluid passage between the pressure responsive member and the outlet end of the passage while the pressure .responsiveimemberis maintained under the :influenoe'of fluid pressure from within the chamber.

7. A power unit, comprising a cylinder, a circular rotor fitting in said cylinder, said rotor having a chamber to receive afiuid'under pressure and .having a fluid passageway leading from the chamber through its periphery, the encircling wall of the cylinder having a circumferentially directed channel therein extending only part way around the cylinder and in the plane of the outlet end of the passageway to receive fluid therefrom, :said channel having an exhaust outlet at one :end, a radially movable abutment carried by the rotor adjacent the outlet end of the passageway, said abutment being movable across said passageway to close the passageway, the abutment being extensible outwardly into the channel and when so positioned-opening the fluid passageway, said :fluid passageway through a portion of its extent upon the side ofthe abutment opposite from the outlet :of .the passageway being formed as a piston cylinder hai ing a lateral out-let, a piston in said cylinder movable under the action of fluid pressure from the chamber to open said lateral outlet for the establishment of uninterrupted fluid flow through the passage to the outlet end of the passage, and a coupling between the piston and the abutment by which the travels therealong, said valve in said adjustment abutment isurged to mnve outwardly when the piston is moved in a direction to uncover the lateral port.

8. A power unit as set forth in claim '7, in which the coupling between the piston and the abutment comprises two sliding parallel members and a spring connection between said parallel members whereby the abutment may move inwardly and outwardly while the piston is maintained in the lateral port uncovering position by the fluid pressure.

9. A power unit, comprising a cylinder, a circular rotor fitting in said cylinder, said rotor having a chamber to receive a fluid under pressure and a fluid passageway leading from the chamber through the periphery of the rotor, the encircling wall of the cylinder having a circumferentially extending channel therein partly encircling the periphery of the rotor in the plane of said fluid passage, a radially movable abutment vane supported for movement transversely of the passage to an outward position in which it extends into said channel and inward from the channel in which it is disposed across and closes ofi the passage, a pressure responsive member within said passage adapted for movement in one direction under the action of fluid pressure from within said chamber, an operative coupling between said pressure responsive element and said abutment by which outward movement of the abutment into the channel is efiected by the pressure responsive element upon movement of the element under pressure of fluid from the chamber, and an exhaust outlet in communication with an end of the channel, said passage opening into the channel between the abutment and the other end of the channel, a shut-off valve mounted for movement across the fluid passage along a path paralleling the axis of rotation of the rotor, and cam means for shifting said valve to fluid passage closing position during such time as the abutment is retracted from said channel.

10. A power unit, comprising a cylinder, a circular rotor fitting in said cylinder, the rotor encircling wall of the cylinder having a circumferentially directed channel therein extending part way around the cylinder, the channel at one end having an exhaust outlet, the opposite end 'of the channel having a wall forming an abutment,

an abutment vane carried by the rotor for radial movement outwardly into said channel, means for efiecting the radial movement of the abutment vane outwardly into the channel, means for introducing fluid into the channel between the abutment vane and the abutment wall, and a fiber strip lying in and covering the bottom surface of the channel from end to end of the channel and against which the outer edge of the abutment vane has sliding contact.

ARTHUR G. MELLINGER. 

